Based on https://github.com/NixOS/nixpkgs/pull/34842, the
nix-instantiate output was pretty-printed and the validity of the github handles
manually verified, by automatically checking whether the user handles exist on
github (https://github.com/userhandle, status 200 or 404).
Each handle under 5 characters was manually checked (because the collision
probability with non-maintainer accounts is high), each missing entry was
manually researched.
The script used is kept in `maintainers/scripts` as an example of how to work
with the mainainers list through nix’ JSON interface.
